Digitorium



(No Model.)

2 sheets sheet 2.

A. LOTHHAMMBR.

DIGITORIUM.

No. 307,863; Patented Nov. 11, 1 884.

UNITED STATES PATENT OFFICE.

ADOLPH LOTHHAMMER, OF SACRAMENTO, GALIFORJIA.

DlGlTORlUM.

EPECIPICA'IION forming part of Letters Patent No. 307,863, datedNovember 11, 1884.

Application filed February 27, 1884.

To all whom it may concern.-

Beit known that I, ADOLPH Lornnmnunn, a citizen of the United States ofAmerica, residing at Sacramento, in the county of Sacramento and Stateof California, have invented certain new and useful ImprovementsinDigitoriums, of which the following is a specification, reference beinghad therein to the accompanying drawings.

The object of my invention is to aid beginners, especially children andpersons of little physical strength, in acquiring a practical knowledgeof the piano, and to gradually strengthen the fingers and wrists whileacquiring such knowledge, at the same time to avoid the noise andannoyance of monotonous practice.

Figure l is a top View of the instrument when in use, showing thefingerboard and the regulating-screws. Fig. 2 is a front view of thefinger-board, showing the keys, their pivots, the springs, and the pointof their at taehment to the rear end o'fthc keys. Fig. 3 is a detailedview showing the regulatingscrews, spring-bar, and springs.

A A, Fig. l, is an ordinary inclosure or box, such as is used 011 asquare piano, and intended for the same purp0se-namcly, that ofinclosing the finger-board and its various attachments. This inclosureis mounted upon a frame similar to and used for the same purpose as thatof a piano.

B, Fig. l, is an ordinary piano finger-board of similar construction,size, and similarly located in the piano-inclosure A A, wherein a and b,respectively, designate the white and blaokkeys. These keys are pivoted,respectively, at a and b, and they extend backward about the same lengthfrom the pivots as in front of them, or to any required but to a uniformlength.

0 C, Fig. 3, are light metallic springs-one for each key, black orwhiteof uniform length, made of common spring-wire, in the form of thehuman knee when about half bent, with one or more coils to each spring,whatever may be needed to give to each the required elasticity. Thelower end of each spring is attached to the upper surface of the rearend of each key, and the upper end to the under surface of the springbarD. In connection with the spring bar it is the peculiar function ofthese springs to regulate the touch of the keys, and make it light orheavy at the will of the operator.

(No model.)

D, Fig. 3, is a wooden bar, its length corresponding to the width of thedigitorium, and of suitable thickness to give it strength that is, fromone-half to one inch thick from three to six inches wide, as use mayrequire. This bar, as stated above, rests upon the upper ends of thesprings C C. By raising or depressing the bar the springs are relaxed ortightened.

E E, Fig.3, are two upright screws, mctallic or wooden, as best adaptedto use, of moderate diameter, from one-half to an inch, according to thesize of the digitorium. The thread is wrought on the lower ends and runsupward about one-half their length, or so far as to relieve the springsfrom all depression by the bar D. At the upper terminus of the threadthe screws are shouldered at E E. They pass through bar D near its endsand rest upon it by means of the shoulders E E. The lower ends arefitted into nuts ff, hereinafter described. The upper ends should be soshaped as to facilitate turning them readily by hand, and may beornamented at will. The screws control the bar D, which controls thesprings, and these regulate the touch of the keys. By this means thetouch of the ii nger-board may be light or heavy, all parts alike, orone part light and the other heavy, at the option of the performer.

ff, Pig. 2, are two wooden or metallic nuts made to receive the screws EE, located on the floor and in the rear corners of the frame A A, ofsuch height as is sufficient to admit all necessary perpendicular motionof the screws.

\Vhen the fingerboard is mentioned in the foregoing specification, thekeys are meantblack and white, front and rear, and pivoted as described.

I claim A digitorium having the finger-board B, in combination with themetallic springs O O, springbar D,.the upright screws E E, and nuts ff,all constructed and arran ed, as and for the purpose specified.

In testimony whereof I aflix my signature in presence of two witnesses.

ADOLPH LOTHHAMMER.

\Vitness es:

D. E. ALEXANDER, F. A. ALEXANDER.

